Variant of multiple sclerosis with dementia and tumefactive demyelinating brain lesions.

We describe an unusual clinical and diagnostic feature of a patient with multiple sclerosis (MS). A 25-year-old woman was admitted to the Neurology department (December 2009) with one month history of rapid cognitive deterioration. She had poor cognition, dysphasia, reduction in visual acuity and temporal pallor of the optic discs. She had prolonged latencies of P100 component of visual evoked potentials (VEPs). Magnetic resonance imaging (MRI)-brain showed multifocal large (≥ 3 cm) white-matter hypointense lesions in T1W and hyperintense in T2W and fluid-attenuated inversion recovery images and patchy enhancement. A diagnosis of tumefactive MS was given. She received two consecutive 5-d courses of 1 g daily intravenous methylprednisolone for 2 mo and oral prednisolone in dose of 80 mg twice/daily in between. At the 3(rd) month, Mini Mental State Examination and VEPs returned to normal but not the MRI. Patient continued oral steroids after hospital discharge (March 2010) for 9 mo with significant MRI improvement after which tapering of steroids started for a year. The patient refused immunomodulation therapy due to her low socioeconomic status. Neither clinical relapse nor new MRI lesions were observed throughout the next 4 years. In spite of the aggressive course of tumefactive MS variant, good prognosis may be seen in some patients.